JP2006049098A - Backlight device and liquid crystal display provided with the backlight device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce cost and improve productivity, by relaxing dimensional accuracy and assembling the accuracy of each member, and improve light efficiency by suppressing leakage of outgoing light outgoing from each light-emitting diode. <P>SOLUTION: A large number of light emission units 15, in each of which a wiring board 17 having a large number of LED's 18 mounted thereon is furnished on a radiation plate 28, are arranged in a plurality of lines on a back portion of a liquid crystal panel 8, to construct a backlight portion 3 for providing illumination light. A reflecting portion 6 for reflecting the outgoing light, from each of the LEDs is constructed of a large number of reflecting sheet pieces 27 attached to each of light-emitting units and a reflecting plate 26 fixed on a reflection plate receiving portion 40 formed in the radiation plate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device having a transmissive liquid crystal panel (LCD) and a backlight device provided in the liquid crystal display device for supplying illumination light.

  Compared with cathode ray tube (CRT) display devices, liquid crystal display devices have a larger display screen, lighter weight, thinner thickness, lower power consumption, etc. Along with a display device (Plasma Display Panel) and the like, it is used for television receivers and various displays. A liquid crystal display device encapsulates liquid crystal between two transparent substrates of various sizes, and changes the light transmittance by changing the direction of liquid crystal molecules by applying a voltage to optically display a predetermined image or the like. A liquid crystal panel is provided.

  Since the liquid crystal display device is not a light emitter, the liquid crystal display device includes a light source unit that supplies illumination light to the liquid crystal panel. As the light source section, a sidelight system that supplies illumination light from the side of the back surface to the liquid crystal panel and a backlight system that directly supplies illumination light from the back surface are generally employed. The backlight unit includes, for example, a light source, a light guide plate that guides illumination light to the liquid crystal panel, a reflection sheet, a lens sheet, a diffusion sheet, and the like, and supplies illumination light over the entire surface of the liquid crystal panel. To do.

  In the backlight unit, a cold cathode fluorescent lamp (CCLF) in which, for example, mercury or xenon is enclosed in a fluorescent tube is used as a conventional light source. Such a backlight unit has problems of solving problems such as insufficient luminous brightness of a cold cathode fluorescent lamp, a relatively short life, or a low brightness region on the cathode side, and uniformity cannot be ensured. It was.

  By the way, in a large sized liquid crystal display device, an area light type backlight (Area Litconfiguration Backlight) is generally provided in which a plurality of long cold cathode fluorescent lamps are arranged on the back surface of a diffusion sheet to supply illumination light to a liquid crystal panel. The apparatus is provided (for example, refer patent document 1). Such area light type backlight devices are also required to solve the above-mentioned problems of the cold cathode fluorescent lamps. In particular, in large-sized television receivers exceeding 30 inches, higher brightness and higher uniformity are required. The problem has become more prominent.

  On the other hand, in the area light type backlight device, instead of the cold cathode fluorescent lamp described above as a light source, a large number of red, green and blue light emitting diodes (LEDs: hereinafter referred to as LEDs) are provided on the back side of the diffusion film. An LED area light type backlight that obtains white light by two-dimensionally arranging LEDs is drawing attention. Such an LED backlight device is designed to reduce the cost as the cost of the LED is reduced and to display a high-luminance image or the like on a large liquid crystal panel with low power consumption.

Japanese Patent Laid-Open No. 6-301034

  In general, an LED backlight device is configured by arranging a large number of LEDs in a matrix, but an array of a large number of LEDs is also provided. The array-type LED backlight device includes a plurality of LEDs mounted on the same axis on the wiring board to form a light-emitting unit body, and a plurality of light-emitting unit bodies arranged on the same axis to form a light-emitting array. Further, a plurality of light emitting arrays are arranged at regular intervals to constitute a light emitting unit. In such an LED backlight device, when large-capacity illumination light respectively emitted from a large number of LEDs is directly incident on the liquid crystal panel through the light guide plate, color unevenness and a lamp image are generated on the liquid crystal panel. There is a problem.

  Therefore, in the LED backlight device, a light diffusing plate is disposed between the light guide plate and the light emitting unit body, and direct incidence of the emitted light emitted from each LED is restricted at a portion facing each LED. The light is reflected or the amount of incident light is controlled and transmitted in the peripheral region. Moreover, in the LED backlight device, so-called side emission type LEDs having directivity for emitting outgoing light mainly in the outer peripheral direction are used as each LED, and the outgoing light emitted from each LED is a light diffusion plate in the peripheral region. So as to be averaged.

  In the LED backlight device, the light emitting unit body is combined with the reflection plate so that the illumination light is efficiently supplied to the liquid crystal panel. In the LED backlight device, the reflection plate reflects the outgoing light reflected by the light diffusing plate and the outgoing light emitted in the outer peripheral direction and makes it incident on the light diffusing plate. In the reflection plate, for example, a large number of guide holes are formed corresponding to each LED, and the light emitting portions of the LEDs facing each other are projected from the guide holes to the liquid crystal panel side.

  By the way, in the conventional LED backlight device, the reflection plate is made of a liquid crystal panel using, for example, a foaming PET (polyethylene terephthalate) plate material containing a fluorescent agent or a plate material in which an aluminum plate is coated with a resin coating. The size was almost the same. In the LED backlight device, a sealed space portion for preventing leakage of illumination light to the outside is formed on the back surface portion of the liquid crystal panel, and the above-described multiple LEDs and respective plates are combined in the sealed space portion. In the LED backlight device, for this reason, heat generated from a large number of LEDs is trapped in the sealed space. In the LED backlight device, a dimensional change occurs in the reflection plate as well as in each optical member due to heat generated from each LED, which greatly affects the positional accuracy between each LED and each guide hole in the reflection plate.

  Further, in the LED backlight device, variations in the dimensional accuracy of the wiring board, the mounting accuracy of each LED, the dimensional accuracy of the back panel, the assembly accuracy of each light emitting unit body and the reflecting plate, etc., due to the configuration of the light emitting array described above. This greatly affects the position accuracy of each guide hole formed in the LED and the reflection plate. In the LED backlight device, a large number of LEDs are mounted with an increase in the size of the liquid crystal panel, and a large number of guide holes are formed while the reflection plate is also increased in size.

  In the conventional LED backlight device, the constituent members are formed with high dimensional accuracy, and each of them is assembled precisely, so that there is a problem that the manufacturing cost increases and the production efficiency is poor. Further, in the LED backlight device, each guide hole formed in the reflection plate has a large diameter in order to cope with a large variation in positional accuracy that occurs between the opposing LEDs as described above. In the LED backlight device, illumination light leaks from the large gap generated between each LED and each guide hole to the back side, the light efficiency is reduced, and a light-shielding structure must be provided on the back side. There was a problem.

  In the conventional LED backlight device, since the reflection plate needs to have a certain degree of mechanical rigidity as the size increases, the reflection plate is formed of a plate material that is coated with an insulating resin using an aluminum plate as a base material. In the LED backlight device, since the aluminum portion of the base material is exposed at the inner peripheral portion of each guide hole formed in the reflection plate, there arises a problem that the insulation from the terminal portion of the opposing LED cannot be maintained. . In the LED backlight device, for this purpose, each guide hole must be formed to have a large diameter so as to maintain a sufficient clearance with the opposing LED, and the above-described leakage of illumination light to the back side is prevented. There was a problem of becoming even larger.

  Therefore, the present invention relaxes the dimensional accuracy and assembly accuracy of each constituent member to reduce costs and improve productivity, and suppresses leakage of light emitted from each light emitting diode from the light guide space. An object of the present invention is to provide a backlight device and a liquid crystal display device in which light efficiency is improved.

  The backlight device according to the present invention that achieves the above-described object includes a plurality of light-emitting unit bodies each having a plurality of light-emitting diodes mounted on the same axis on the main surface of the wiring board. A light emitting array is configured, and a plurality of light emitting arrays are arranged at equal intervals on the back surface of the transmissive liquid crystal panel via an optical sheet block, and illumination light is supplied. The backlight device includes a plurality of reflection sheet pieces and a reflection plate that are assembled to a heat dissipation plate that supports a plurality of wiring boards and constitutes each light emitting array.

  In the backlight device, the heat radiating plate is formed of a metal material having thermal conductivity, and a board fitting portion is provided on the main surface of the base portion, which is placed on the same axis and supports the wiring boards arranged in the length direction. At the same time, a reflection plate receiving portion is formed along both sides of the board fitting portion. In the backlight device, each reflecting sheet piece is formed of a rectangular piece having a length corresponding to a predetermined number of light emitting diodes by a sheet material having reflection characteristics, and having a width smaller than the width of the heat radiating plate. A large number of guide holes for penetrating the light emitting portions are provided on the same axis. In the backlight device, the reflection plate is formed in a plate material having reflection characteristics so as to have substantially the same outer shape as the liquid crystal panel, and is formed in a position corresponding to each light-emitting array and penetrates the light-emitting portion of each light-emitting diode. A guide opening is provided.

  In the backlight device, each reflecting sheet piece projects from the light emitting portion of the light emitting diode facing each guide hole and is assembled to the heat radiating plate, and the reflecting plate is superimposed on each reflecting sheet piece. It is joined to the reflection plate receiving part. In the backlight device, each light emitting diode protrudes from the guide opening portion of the reflection plate through the guide hole of each reflection sheet piece and faces the back surface portion of the liquid crystal panel. In the backlight device, the reflection sheet pieces are assembled for each light emitting unit body, so that the guide holes of the reflection sheet pieces and the light emitting diodes opposed to each other do not require much dimensional accuracy, and the constituent members Thus, the positioning can be performed accurately without being affected by the assembly accuracy and the dimensional accuracy. In the backlight device, each reflection sheet piece is held by a reflection plate bonded to the heat dissipation plate, thereby preventing the outgoing light emitted from each light emitting diode from leaking to the back side.

  In the backlight device, a heat pipe is assembled in a heat pipe fitting portion formed over the entire length direction at the base of each heat radiating plate while keeping the inner wall in close contact with the light emitting plate. The generated heat generated and transmitted to each heat radiating plate is efficiently conducted to the heat radiating means so that the heat is radiated.

  Further, in the backlight device, a dustproof elastic material that seals the board fitting portion is joined to the reflection plate receiving portions at the side portions of the heat radiating plate located on both sides. In the backlight device, each dustproof elastic material closes the opened side portion of the board fitting portion that supports the wiring board, thereby preventing dust and the like from entering the board fitting portion. Improvement is achieved.

  Further, in the backlight device, each guide opening formed in the reflecting plate corresponding to each light emitting array is divided into lengths that are located on the same axis and penetrate a plurality of light emitting diodes by the bridge portion. The plurality of guide openings are formed. In the backlight device, a reflective sheet piece is assembled to each wiring board through the light-emitting diodes facing each other through each guide hole, and the reflection plate is joined to the reflection plate receiving portion of each heat radiation plate, thereby reflecting Each bridge portion of the plate presses the reflecting sheet piece toward the heat radiating plate to prevent the plate from rising.

  Further, in the backlight device, the reflective sheet piece is formed of an insulating synthetic resin sheet material, and the reflective plate is formed of an aluminum plate as a base material. In the backlight device, the inner peripheral edge of each guide hole of each reflecting sheet piece having a small diameter is inward over the entire inner periphery of each guide opening of the reflecting plate from which the aluminum material is exposed. It becomes a structure that protrudes and is combined. Therefore, in the backlight device, electrical insulation between the aluminum portion of the reflection plate and the terminal portion of each light emitting diode is maintained by each reflection sheet piece.

  The liquid crystal display device according to the present invention that achieves the above-described object includes a transmissive liquid crystal panel and a large number of light emitting diodes, and emits a large amount of illumination light from the light emitted from each light emitting diode to the liquid crystal panel. The backlight unit that supplies the light, the optical conversion unit that performs a predetermined optical conversion process on the illumination light and supplies it to the liquid crystal panel, and the illumination light emitted from the backlight unit is supplied to the liquid crystal panel in a uniform state A light guide section, a reflection section that reflects the emitted light emitted from each light emitting diode toward the periphery toward the light guide section, and a heat radiation section that radiates heat generated in the backlight section. In the liquid crystal display device, the backlight unit is configured to form a light emitting unit body by mounting a large number of light emitting diodes on the same axis on the main surface of the wiring board, and a plurality of light emitting unit bodies are arranged on the back surface of the liquid crystal panel. A plurality of light emitting arrays are formed by arranging them at equal intervals on the same axis. The liquid crystal display device is composed of a functional optical sheet laminate in which an optical conversion unit is formed by laminating a plurality of functional optical sheets disposed between a liquid crystal panel and a backlight unit. A polarization function, a function of correcting a phase difference to achieve a wide-angle visual field and anti-coloring, a diffusion function, and the like are supplied from a backlight unit and illumination light is supplied to a liquid crystal panel in a stable state.

  In the liquid crystal display device, the light guide unit includes a diffusion light guide plate and a light diffusion plate arranged on the back surface of the optical conversion unit. The light guide part is formed with a diffusion light guide plate having a slight thickness, for example, by milky white light guide resin material, and is averaged from the entire surface by diffusing the incident illumination light inside, so that the optical conversion part To supply. In the light guide unit, the light diffusion plate selectively performs a reflection / diffusion operation and a transmission operation on the illumination light to equalize the luminance, and supplies the light to the diffusion light guide plate. The light diffusing plate is made of, for example, a transparent resin material, and a plurality of light adjusting portions having light reflecting and diffusing properties are formed at portions facing the respective light emitting diodes. The light diffusing plate regulates the amount of light emitted from each light emitting diode directly below by each dimming unit and suppresses the generation of a partial high-brightness region. Light is supplied to the diffused light guide plate.

  In the liquid crystal display device, the heat dissipating part is formed of a metal material having thermal conductivity, and a board fitting part is provided on the main surface of the base part, which is arranged on the same axis and supports the wiring boards arranged in the length direction. It has a plurality of heat dissipation plates. In the heat dissipating part, each heat dissipating plate constitutes a support member for the light emitting unit body, and the heat dissipating arrays are arranged on the same axis line at equal intervals on the back surface of the liquid crystal panel and respectively correspond to a plurality of light emitting arrays. Each heat dissipating plate is formed with a standing wall-like reflecting plate receiving portion along both sides of the board fitting portion, and the reflecting plate is joined to the reflecting plate receiving portion.

  Each heat dissipating plate has concave groove-like heat pipe fitting parts located on the same axis line in the state of being arranged in the length direction on the bottom face part of the base part on which the board fitting part is formed over the entire length direction. Each is formed over. Each heat dissipating plate is assembled with a heat pipe in close contact with the inner wall within the heat pipe fitting portion, and heat generated from each light emitting diode is conducted to the heat dissipating means by the heat pipe.

  In the liquid crystal display device, the reflection part reflects the emitted light emitted from each light emitting diode to the surroundings and the emitted light reflected by the light adjustment part of the light diffusion plate to the light guide part. The reflection section includes a large number of reflection sheet pieces provided for each wiring board and a reflection plate formed with an outer dimension substantially equal to that of the liquid crystal panel. Each reflection sheet piece is formed in a rectangular piece shape having a sheet material having a reflection characteristic and substantially the same length as a wiring board on which a predetermined number of light-emitting diodes are mounted and slightly smaller than the width of the heat dissipation plate. Each reflecting sheet piece is provided with a large number of guide holes on the same axis so as to penetrate the light emitting portions of the respective light emitting diodes.

  In the liquid crystal display device, each reflection sheet piece is assembled to the heat radiation plate by projecting the light emitting portion of the light emitting diode facing from each guide hole, and the reflection plate is superimposed on each reflection sheet piece to reflect the reflection of each heat radiation plate. It is joined to the plate receiving part to constitute a reflecting part. In the liquid crystal display device, a plurality of light emitting diodes projecting from the respective guide holes of the respective reflecting sheet pieces project their respective light emitting portions from the guide opening and face the back surface of the liquid crystal panel.

  In a liquid crystal display device, heat generated from a large number of light emitting diodes is efficiently radiated through a heat radiating plate having a function of supporting a wiring board. Furthermore, in the liquid crystal display device, the heat pipe is assembled in a heat pipe fitting portion formed over the entire length direction at the base portion of each heat dissipating plate while keeping the inner wall in close contact with the heat pipe. The heat generated from each light emitting diode and conducted to each heat radiating plate is efficiently conducted to the heat radiating means so that the heat is radiated.

  In the liquid crystal display device, each guide opening formed in the reflective plate corresponding to each light emitting array is divided into lengths that are located on the same axis and penetrate a predetermined number of light emitting diodes by each bridge portion. It is constituted by a plurality of guide openings. In the liquid crystal display device, each bridge portion presses each reflecting sheet piece toward the heat radiating plate in a state in which the reflecting plate is bonded onto the reflecting plate receiving portions of a large number of heat radiating plates, thereby preventing floating.

  In the liquid crystal display device, the reflection sheet piece is formed of an insulating synthetic resin sheet material, and the reflection plate is formed using an aluminum plate as a base material. In the liquid crystal display device, the inner peripheral edge of each guide hole of each of the opposing reflecting sheet pieces having a small diameter is inward over the entire inner periphery of each guide opening of the reflective plate from which the aluminum material is exposed. It becomes a structure that protrudes and is combined. Accordingly, in the liquid crystal display device, each reflection sheet piece maintains electrical insulation between the aluminum portion of the reflection plate and the terminal portion of each light emitting diode, thereby improving reliability.

  According to the present invention, a plurality of light emitting diodes are mounted on the same axis on the main surface of the wiring board to constitute a light emitting unit body, and a plurality of light emitting unit bodies are arranged on the same axis on the back surface of the liquid crystal panel. A plurality of reflective sheet pieces assembled to each light emitting unit body and each of the light emitting units are arranged in a backlight section in which a plurality of the light emitting arrays are arranged at equal intervals. By attaching a reflective part consisting of a reflective plate to be joined on the reflective plate receiving part formed on the heat dissipation plate, a large amount of illumination light is supplied in a uniform state from the backlight part even for large liquid crystal panels. In this way, high brightness image display is performed.

  According to the present invention, a plurality of guide holes for projecting the light emitting portions of the light emitting diodes facing the reflecting sheet pieces assembled for each light emitting unit body are formed, and the light emitting portions of the plurality of light emitting diodes are projected. A reflection plate in which a plurality of guide openings are formed holds each reflection sheet piece and is bonded onto the reflection plate receiving portion of the heat radiating plate. According to the present invention, since the guide hole is formed in the reflection sheet piece that is held by the reflection plate and directly combined with the wiring board, each guide hole and the light emitting diode facing each other are precisely positioned. Therefore, according to the present invention, a simple configuration that reduces the dimensional accuracy and assembly accuracy of each component and the assembly process can be achieved to reduce costs and improve productivity, and emit light from each light emitting diode. It is possible to suppress the leakage of the illumination light and improve the light efficiency to display with high luminance.

  Hereinafter, a transmissive liquid crystal color display device (hereinafter abbreviated as a liquid crystal display device 1) 1 shown as an embodiment of the present invention will be described in detail with reference to the drawings. The liquid crystal display device 1 is used, for example, in a television receiver or a display monitor device having a large display screen of 30 inches or more. As shown in FIGS. 1 and 2, the liquid crystal display device 1 includes a liquid crystal panel unit 2 and a backlight unit 3 that is combined with the back side of the liquid crystal panel unit 2 and emits large-capacity illumination light. Yes. The liquid crystal display device 1 performs optical conversion processing on the illumination light emitted from the backlight unit 3 between the liquid crystal panel unit 2 and the backlight unit 3 and supplies the illumination light to the liquid crystal panel unit 2. Part 4, light guide part 5 for supplying illumination light in a uniform state to liquid crystal panel unit 2, and reflection for reflecting illumination light emitted toward the periphery from backlight part 3 toward light guide part 5 A part 6 and a heat radiating part 7 for radiating heat generated in the backlight part 3 are arranged.

  In the liquid crystal display device 1, the liquid crystal panel unit 2 includes a liquid crystal panel 8 having a large display screen size of 30 inches or more. As shown in FIG. 9 and the holder frame member 10 are sandwiched and held via the spacer 11, the guide member 12, and the like. In the liquid crystal display device 1, a holder frame member 10 and a back panel 13, which will be described in detail later, constitute a so-called chassis member in which constituent members are assembled, and are fixed to a mounting portion of a housing (not shown). The liquid crystal display device 1 is combined with a cover glass on the front side of the liquid crystal panel 8 (not shown).

  Although not described in detail, the liquid crystal panel 8 encloses a liquid crystal between the first glass substrate and the second glass substrate, which are held at a distance from each other by spacer beads, and applies a voltage to the liquid crystal. Change the light transmittance by changing the direction of the molecule. The liquid crystal panel 8 has a striped transparent electrode, an insulating film, and an alignment film formed on the inner surface of the first glass substrate. In the liquid crystal panel 8, a color filter of three primary colors, an overcoat layer, a striped transparent electrode, and an alignment film are formed on the inner surface of the second glass substrate.

  In the liquid crystal panel 8, a deflection film and a retardation film are bonded to the surfaces of the first glass substrate and the second glass substrate, respectively. In the liquid crystal panel 8, an alignment film made of polyimide is arranged in a horizontal direction with liquid crystal molecules as an interface, and the deflection film and the retardation film are achromatic and whitened to achieve full color using a color filter. The received image is displayed in color. The liquid crystal panel 8 is not limited to such a structure, and may of course be a liquid crystal panel having various configurations conventionally provided.

  The liquid crystal display device 1 is combined on the back side of the liquid crystal panel unit 2 described above to constitute a light guide space portion 14 in which the backlight portion 3 is optically sealed as shown in FIG. The backlight unit 3 includes a light emitting array 16 in which a predetermined number of light emitting unit bodies 15 are arranged on the same axis, and a plurality of rows of light emitting arrays 16 are arranged in parallel with each other at a predetermined interval. In detail, as shown in FIG. 3, the backlight unit 3 includes three light emitting unit bodies 15 arranged in the length direction to form a light emitting array 16 for one row, and the light emitting array 16 is arranged in six rows in the height direction. Configure side by side. The backlight unit 3 includes a total of 3 × 6 = 18 light emitting unit bodies 15.

  In the backlight unit 3, each light emitting unit body 15 includes a wiring board 17, a plurality of LEDs 18 mounted on the wiring board 17, an input connector 19, an output connector 20, and the like. The backlight unit 3 is mounted on the wiring board 17 of each light emitting unit body 15 with a total of 25 LEDs 18 that are a combination of red LEDs, green LEDs, and blue LEDs positioned on the same axis. Therefore, the backlight unit 3 includes 25 × 3 = 75 LEDs for each light emitting array, and 75 × 6 = 450 LEDs 18 in total for 6 columns.

  As shown in FIGS. 2 and 5, each LED 18 holds the light emitting portion 18 a by a resin holder 18 b and pulls out a pair of terminals 18 c from the resin holder 18 b. Although not described in detail, each LED 18 is a so-called side emission type LED having directivity for emitting the main component of the emitted light in the outer peripheral direction of the light emitting portion 18a. Note that the number of the light emitting unit bodies 15 and the number and interval of the LEDs 18 mounted on each of the backlight units 3 are appropriately determined depending on the size of the liquid crystal panel 8 and the light emission capability of each LED 18.

  In the light emitting unit 15, all the wiring boards 17 are formed with the same specifications, and although not shown, there are wiring patterns for connecting the LEDs 18 in series to the wiring boards 17, lands for connecting the terminals of the LEDs 18, and the like. Is formed. On each wiring board 17, an input connector 19 is mounted in the vicinity of one side in the width direction and on one side, and an output connector 20 is mounted on the other side.

  As shown in FIG. 3, each light emitting array 16 has the light emitting unit bodies 15 arranged in the same row with the wiring board 17 in the same direction. The light-emitting array 16 has an odd-numbered light-emitting array in the first, third, and fifth rows, and one edge portion on the side where each wiring board 17 is mounted with the input connector 19 and the output connector 20, respectively. The light emitting unit bodies 15 are arranged so that is directed downward. The light emitting array 16 has the second row, the fourth row, and the sixth row even-numbered row light-emitting arrays on the one side edge portion on the side where each wiring board 17 is mounted with the input connector 19 and the output connector 20, respectively. The light emitting unit bodies 15 are arranged so that is directed upward.

  Therefore, each light emitting array 16 is arranged in the same row so that each light emitting unit body 15 faces the input connector 19 and the output connector 20 of each adjacent wiring board 17. In addition, each light emitting array 16 is arranged in an odd number column and an even number column so that the input connector 19 and the output connector 20 of each wiring board 17 facing each light emitting unit body 15 face each other.

  In each light emitting array 16, each light emitting unit body 15 is connected in series by a lead wire with a connector (not shown) in the same column. As described above, each light emitting array body 15 is made to emit light by making the input connector 19 and the output connector 20 face each other. The shortest wiring is performed between the unit bodies 15. Each light emitting array 16 has an input connector 19 positioned on the right end side of the light emitting unit body 15 arranged on the right side in each odd-numbered row, and an output connector on the left end side of the light emitting unit body 15 arranged on the left side. 20 are located and arranged. Further, each light emitting array 16 has an output connector 20 positioned on the left end side of the light emitting unit bodies 15 arranged on the left side in the even-numbered columns, and inputs to the right end side of the light emitting unit bodies 15 arranged on the right side. Connector 19 is positioned and arranged. In each light emitting array 16, the lead wires are routed using the space in the length direction formed between the odd and even columns. The lead wires are drawn from each space and drawn to each space through a drawing opening (not shown) formed in the back panel 13 and are bundled by a clamper or the like in each space.

  As described above, the backlight unit 3 holds and guides the lead wires using the spaces formed between the light emitting arrays 16, thereby improving the efficiency of the space and simplifying the wiring process. In the backlight unit 3, the wrong combination of the light emitting unit bodies 15 is identified in the same row and between rows depending on the positions of the input connector 19 and the output connector 20 mounted on each wiring board 17. . In the backlight unit 3, each light emitting array 16 is designed to simplify the wiring structure between the wiring boards 17, the wiring process, or to share the lead wires.

  In the liquid crystal display device 1, large-capacity illumination light based on the emitted light emitted from each LED 18 of the backlight unit 3 described above is supplied to the liquid crystal panel 8 via the optical conversion unit 4. The optical conversion unit 4 has an optical sheet laminate in which a plurality of optical sheets having an outer shape substantially equal to the outer shape of the liquid crystal panel 5 are stacked. The optical conversion unit 4 is an optical function sheet that the optical function sheet laminate omits the details, but decomposes the illumination light supplied from the backlight unit 3 into orthogonal polarization components, compensates for the phase difference of the illumination light, and wide angle It consists of a plurality of optical function sheets having various optical functions, such as an optical function sheet for reducing the viewing angle and preventing coloring, or an optical function sheet for diffusing illumination light.

  As shown in FIG. 2, the optical conversion unit 4 is combined with the main surface of the diffusion light guide plate 21 of the light guide unit 5, which will be described later, as shown in FIG. 2, and via the holding bracket member 22 assembled to the back panel 13. Thus, the liquid crystal panel 5 is arranged on the back side with a predetermined facing distance. The optical conversion unit 4 is not limited to the above-described optical functional sheet laminate, and as other optical functional sheets, for example, a luminance improving film for improving luminance, a diffusion between upper and lower two sheets sandwiching a retardation film and a prism sheet. An optical function sheet such as a sheet may be provided.

  In the liquid crystal display device 1, the light conversion unit 4 guides the light in the light guide space 14 in a state where the illumination light supplied from the backlight unit 3 has a uniform luminance over the entire surface by the light guide unit 5. Is supplied to the liquid crystal panel 8. The light guide unit 5 includes a diffusion light guide plate 21 and a diffusion plate 23, and is disposed in the light guide space 14 while being held at a predetermined facing interval by an optical stud member 25 as will be described in detail later.

  The diffusion light guide plate 21 is made of a plate body that is substantially the same size and slightly thick as the liquid crystal panel 8 formed from a milky white synthetic resin material having a light guide property, such as an acrylic resin or a polycarbonate resin. The diffusion light guide plate 21 is combined with the optical function sheet laminate of the optical conversion unit 4 on one main surface, and the outer peripheral portion is held by the bracket member 22. The diffusion light guide plate 21 diffuses the illumination light incident from the other main surface by appropriately refracting and irregularly reflecting inside, and uniforming the luminance from the main surface side to the entire surface, thereby converting the optical conversion unit 4 is incident.

  The diffusion plate 22 is formed of a plate body having substantially the same size as the liquid crystal panel 8 formed of a transparent synthetic resin material such as an acrylic resin, and is disposed opposite to the backlight unit 3 with a predetermined interval. By this, it has a function which controls the incident state of the emitted light radiate | emitted from each LED18. As shown in FIG. 2, dimming patterns 24 are formed on the diffusion plate 22 at portions facing the light emitting portions 18 a of the respective LEDs 18.

  Each light control pattern 24 is configured by printing a circular pattern having a slightly larger diameter than the light emitting portion 18a of the LED 18 with ink having light reflection / diffusion characteristics. Each dimming pattern 24 uses an ink prepared by mixing an ink material containing a light shielding agent and a diffusing agent at a predetermined ratio, and is precisely formed by, for example, a screen printing method or the like. For ink, as a light-shielding agent, for example, titanium oxide, barium sulfide, calcium carbonate, alumina oxide, zinc oxide, nickel oxide, calcium hydroxide, lithium sulfide, iron trioxide, methacrylic resin powder, mica (sericite), porcelain clay Powder, kaolin, bentonite, gold powder, pulp fiber or the like is used. In the ink, for example, silicon oxide, glass beads, glass fine powder, glass fiber, liquid silicon, crystal powder, gold plating resin beads, cholesteric liquid crystal liquid, recrystallized acrylic resin powder, and the like are used as a diffusing agent.

  The diffuser plate 22 reflects the component emitted directly upward from the emitted light emitted from the light emitting portion 18a of the LED 18 in which the respective dimming patterns 24 are arranged immediately below. The diffusing plate 22 makes the emitted light incident in a region where each light control pattern 24 is not formed, that is, a region not directly facing each light emitting array 16. In this way, the diffusion plate 22 regulates the emitted light that is emitted from each LED 18 and directly incident by each dimming pattern 24, thereby reducing the occurrence of a partial high-luminance region and making the luminance uniform. Light is supplied to the diffused light guide plate 21 from the entire surface.

  The diffusing plate 22 is composed of a large number of dots formed in each light control pattern 24 in a region having a larger diameter than the light emitting portion 18a of the LED 18, and transmits a part of the emitted light and reflects and diffuses a part thereof. By doing so, the amount of incident light may be limited. In this case, each of the light control patterns 24 is formed so that each light control pattern 24 has a dot density that is close to the peripheral portion, thereby restricting the amount of incident light at the central portion and shifting the position of the LED 18. You may comprise as what is called a gradation pattern to absorb. Since the diffusion plate 22 has a phenomenon that the illumination light is condensed in the region between the light emitting arrays 16 by using the side emission type LED 18 as described above, the dimming pattern 24 is formed in a vertically long shape. You may make it suppress generation | occurrence | production of this.

  In the liquid crystal display device 1, a part of the emitted light emitted from each LED 18 and incident on the diffusion plate 23 beyond the critical angle is reflected on the surface of the diffusion plate 23. In the liquid crystal display device 1, the outgoing light emitted from the LEDs 18 of the backlight unit 3 to the surroundings, the outgoing light reflected by the surface of the diffusion plate 23, or the outgoing light reflected by the dimming patterns 24 is reflected. The light is reflected by the portion 6 and efficiently supplied to the light guide portion 5 through the diffusion plate 23. In the liquid crystal display device 1, the reflection portion 6 is repeatedly reflected between the diffuser plate 23 and the reflectance is improved by the principle of increased reflection.

  As shown in FIGS. 2 and 4, the reflection unit 6 includes a single large reflection plate 26 and a large number of reflection sheet pieces 27 provided for each light emitting unit body 15. The reflection portion 6 is positioned by a heat radiating plate 28 and an optical stud member 25 constituting the heat radiating portion 7 and combined with the backlight portion 3 as will be described in detail later. The sheet piece 27 is held.

  The reflection plate 26 is a large-sized member having a relatively high surface accuracy with no distortion and substantially the same shape as the liquid crystal panel 8 that is combined with the light guide unit 5 while being opposed to each other. Of mechanical rigidity is required. Therefore, the reflecting plate 26 is formed by joining, for example, a reflecting material 30 made of foaming PET or the like containing a fluorescent agent on the surface of an aluminum plate 29 as a base material. The reflection plate 26 may be made of not only an aluminum material but also a stainless steel plate having a mirror surface. Further, when the reflective plate 26 is a relatively small-sized liquid crystal display device, the reflective plate 26 may be formed of, for example, foaming PET containing a fluorescent agent. Foamable PET is lightweight, has a high reflectivity characteristic of about 95%, and has features such as scratches on the reflecting surface having a color tone different from that of the metallic luster color, and the conventional liquid crystal display device. It is also used.

  As shown in FIG. 3, six rows of guide openings 31 are formed in the reflection plate 26 so as to correspond to the respective light emitting arrays 16. In detail, each guide opening 31 is located on the same axis and is divided into a plurality of horizontally long unit guide openings 32 a to 32 n (collectively referred to as unit guide openings 32) divided by bridge portions 33. Composed. Each unit guide opening 32 has a width that is slightly larger than the outer diameter of the light emitting portion 18a of the LED 18, and is formed with a length sufficient to allow each of the five LEDs 18 to pass therethrough.

  Therefore, since the guide opening 31 has 75 LEDs 18 in each light emitting array 16, it is constituted by 75 ÷ 5 = 15 unit guide openings 32 for each column. The guide opening 31 is not limited to such a configuration, and may be configured by one opening having a length corresponding to the entire length of each light emitting array 16. However, the guide openings 31 pass through several LEDs 18 because each bridge portion 33 holds the mechanical rigidity of the reflection plate 26 and also functions as a portion for holding the reflection sheet piece 27 as will be described later. It is preferable that the gaps are formed with a certain interval.

  For the reflection sheet piece 27, a member having high reflection characteristics such as the above-described foaming PET material is used. The reflection sheet piece 27 is substantially the same length as each wiring board 17 and has a slightly larger width and is slightly larger than the width of the heat radiating plate 28. It is formed in a rectangular piece having a small width. In the reflection sheet piece 27, 25 guide holes 34 are formed corresponding to the 25 LEDs 18 provided on the light emitting unit bodies 15 on the same axis. Each guide hole 34 is formed on the reflective sheet piece 27 on the same axis line and aligned in the length direction, and each of the guide holes 34 is a circular hole having an inner diameter substantially equal to that of the light emitting portion 18 a of each LED 18.

  For each light emitting unit body 15, the reflection sheet piece 27 is combined with the wiring substrate 17 that is supported by the heat radiating plate 28 through the light emitting portions 18 a of the LEDs 18 that are opposed from the respective guide holes 34. The reflection sheet piece 27 is formed in a size corresponding to each light emitting unit body 15 and can be accurately positioned with each LED 18 facing from each guide hole 34 by being directly combined with the wiring board 17. It is. Therefore, the reflection sheet piece 27 is protruded from each guide hole 34 in a state where the outer peripheral portion of the light emitting portion 18a of each LED 18 is in close contact with the inner peripheral wall thereof. The reflection sheet piece 27 is formed to have a width substantially the same as or slightly smaller than a board fitting recess 38 of the heat radiating plate 28 described later, and the opening edge of each guide hole 34 is locked on the upper surface of the resin holder 18b of the LED 18. You may do it.

  As shown in FIGS. 3 and 5, the reflector 6 penetrates the light emitting part 18 a of each LED 18 facing the respective light emitting unit bodies 15 through the reflecting sheet pieces 27 from the respective guide holes 34 to the wiring board 17. Combined. The reflection part 6 is fixed on each heat radiating plate 28 so that the reflection plate 26 is overlapped on each reflection sheet piece 27 and the details will be described later. In the reflecting portion 6, a predetermined number of guide holes 34 on the reflecting sheet piece 27 side are caused to face each guide opening 31 of the reflecting plate 26, so that the light emitting portion 18 a of the LED 18 is penetrated from each guide opening 31. It faces the diffusion plate 23.

  In the reflection portion 6, as described above, each reflection sheet piece 27 is formed of an insulating foamable PET material, and the reflection plate 26 is formed of a laminate of an aluminum plate 29 and a foamable PET material 30. In the reflection part 6, as shown in FIG. 5, each reflection sheet piece 27 made of an insulating material has a small diameter relative to the inner peripheral edge of each guide opening 31 of the reflection plate 26 from which the aluminum material is exposed. The inner peripheral edge of each guide hole 34 protrudes inward over the entire periphery and is combined. Therefore, in the reflection portion 6, electrical insulation between the aluminum portion of the reflection plate 26 and the terminal 18 c of each LED 18 is maintained by each reflection sheet piece 27.

  In the reflection part 6, the reflection plate 26 is assembled after the reflection sheet pieces 27 are combined for each light emitting unit body 15 as described above. In the reflection part 6, each reflection sheet piece 27 is held by pressing the reflection sheet piece 27 onto the heat dissipation plate 28 by fixing the reflection plate 26 on the heat dissipation plate 28. In the reflecting portion 6, as described above, the reflecting plate 26 divides the unit guide opening portions 32 through which the five LEDs 18 protrude through the bridge portions 33 to form the guide opening portions 31. Therefore, in the reflection part 6, each bridge | bridging part 33 hold | maintains these reflection sheet pieces 27 still more reliably by pressing each reflection sheet piece 27 at predetermined intervals with respect to the length direction. The reflecting portion 6 does not require a structure for preventing the reflection sheet piece 27 from being lifted or oscillating, but the structure and the assembly can be simplified by such a configuration.

  By the way, as described above, the reflecting portion 6 has the reflecting plate 26 having a large size equivalent to that of the liquid crystal panel 8, and the supporting portion 13a and the optical stud member 25 formed on the back panel 13 as shown in FIG. And is combined with the backlight unit 3. When the reflection plate 26 is configured by a circular hole that penetrates each LED 18 one by one, like the reflection sheet piece 27, the reflection plate 26 is extremely difficult to position the circular hole and the LED 18. Become. The reflection portion 6 forms the reflection plate 26 with high dimensional accuracy, and requires the correspondence of positioning and assembling each member with high accuracy, thereby greatly increasing costs from high-precision component manufacturing and assembly processes. As a result, the reflection plate 26 is distorted by the heat change.

  The reflection part 6 is configured by combining the reflection plate 26 and a large number of reflection sheet pieces 27, thereby preventing a gap from being generated in the outer peripheral part of each LED 18. The reflection unit 6 can prevent a part of the emitted light emitted from each LED 18 from leaking to the back side from the gap of the outer peripheral portion, and can improve the light efficiency and perform high luminance display. To do. The reflection unit 6 can simplify the structure by eliminating the need for a structure that shields leaked light from the back side.

  In the reflecting portion 6, as described above, the reflecting plate 26 and the multiple reflecting sheet pieces 27 are combined to form the guide hole 34 formed in each reflecting sheet piece 27 with the light emitting portion 18a of each LED 18 and precisely. In close contact with the outer periphery. Therefore, in the reflection part 6, the emitted light radiate | emitted from each LED18 is prevented from leaking to the back side from the clearance gap between the inner peripheral wall of the guide hole 34, and the outer peripheral part of the light emission part 18a.

  In the liquid crystal display device 1, when the surface luminance of the reflection plate 26 of the reflection portion 6 configured as described above was measured, a result of 6135 cd / m 2 at the center luminance was obtained. On the other hand, in the conventional liquid crystal display device that does not have the reflection sheet piece 27, the surface luminance of the reflection plate measured by the same method was 5716 cd / m 2. Therefore, in the liquid crystal display device 1, it was confirmed that about 7% improvement in luminance was achieved.

  In the reflection part 6, the reflective sheet piece 27 is formed in a size that is combined for each light emitting unit body 15, but in a size that combines two or three according to the size of the light emitting unit body 15. You may form, and you may form in the magnitude | size combined across several light emission unit bodies 15. FIG. However, when the reflecting sheet piece 27 is too large, it is difficult to accurately align the guide holes 34 and the LEDs 18, and the effect of the laminated structure described above cannot be achieved. Formed.

  In the liquid crystal display device 1, a large number of optical stud members 25 are attached to the back panel 13, and the optical function sheet body that constitutes the optical conversion unit 4 described above via the optical stud members 25, and the light guide unit 5. The diffusing light guide plate 21 and the diffusing plate 23 constituting the reflector and the reflecting plate 26 constituting the reflecting portion 6 are positioned with respect to each other and the parallelism between the opposing principal surfaces is accurately maintained over the entire surface. Has been. In the liquid crystal display device 1, color unevenness and the like are prevented by maintaining the distance and parallelism between the large-sized plates.

  In the liquid crystal display device 1, for the combination with the optical stud member 25, a large number of fitting holes 23 a are formed in the diffusion plate 23 described above, and a large number of fitting holes 26 a are formed in the reflection plate 26. Is done. The fitting holes 23a and 26a are formed between the rows of the light emitting arrays 16 and the axes thereof being aligned in a state where the diffusion plate 23 and the reflection plate 26 are combined.

  Each optical stud member 25 is a member formed integrally with a milky white synthetic resin material having light guiding properties, mechanical rigidity, and a certain degree of elasticity, such as a polycarbonate resin. For example, as shown in FIGS. Each is attached to a mounting portion 35 formed integrally with the panel 13. The back panel 13 is formed with a large number of attachment portions 35 that are formed integrally with a substantially trapezoidal convex portion on the inner surface side. As for the attachment part 35, the upper surface comprises the mounting surface of the diffusion plate 23, and the attachment hole 35c is each penetrated and provided. The attachment portion 35 is formed so as to be positioned between the rows of the light emitting arrays 16 in the state where the backlight portion 3 described above is combined with the back panel 13.

  As shown in FIG. 6, each optical stud member 25 has a shaft-like base portion 25a, a fitting portion 25b formed at the tip of the shaft-like base portion 25a, and a predetermined distance from the fitting portion 25b. A flange-shaped first receiving plate portion 25c integrally formed around the circumference of the shaft-shaped base portion 25a, and a single piece around the circumference of the shaft-shaped base portion 25a with a predetermined interval from the first receiving plate portion 25c. And a flange-shaped second receiving plate portion 25d. Each optical stud member 25 has an axial base 25a formed with an axial length that defines the facing distance between the mounting portion 35 of the back panel 13 and the diffusion light guide plate 21, and a predetermined length from the second receiving plate portion 25d. A step portion 25e is formed at the height position.

  Each optical stud member 25 has a long conical shape in which the shaft-like base portion 25a has a slightly larger diameter than the fitting hole 23a in which the step portion 25e is formed in the diffusion plate 23, and gradually becomes smaller in diameter toward the tip portion. Is formed. Each optical stud member 25 is formed with an axial stealing hole 25f in the axial base portion 25a located slightly above the stepped portion 25e. The meat stealing hole 25f is formed in the range of the part where the outer diameter is larger than that of the fitting hole 23a of the diffusion plate 23 in the shaft-like base part 25a, and imparts convergence to this part.

  Each optical stud member 25 is formed with an interval in which the first receiving plate portion 25 c and the second receiving plate portion 25 d maintain the facing distance between the diffusion plate 23 and the reflection plate 26. Each optical stud member 25 has a shaft-like base portion 25a formed with the first receiving plate portion 25c and the second receiving plate portion 25d at substantially the same diameter as the fitting hole 23a of the diffusion plate 23. Each optical stud member 25 has a fitting portion 25b having an outer diameter that is substantially equal to the outer diameter of the mounting hole 35a formed in the mounting portion 35 on the back panel 13 side, and this mounting hole in the axial direction. The cross section gradually becoming larger than the inner diameter of 35a has a substantially truncated cone shape. Each optical stud member 25 is given converging habits when the fitting portion 25b forms a slit 25g from the large diameter portion toward the tip side.

  Each optical stud member 25 is formed such that the distance between the large diameter portion of the fitting portion 25 a and the first receiving plate portion 25 c is substantially equal to the sum of the thickness of the back panel 13 and the thickness of the diffusion plate 23. Each optical stud member 25 has a first receiving plate portion 25c slightly larger in diameter than the inner diameter of the fitting hole 23a of the diffusion plate 23, and a second receiving plate portion 25d of the fitting hole 26a of the reflecting plate 26. The diameter is slightly larger than the inner diameter.

  In the liquid crystal display device 1, the reflection plate 26 is mounted on the mounting portion 35 of the back panel 13 with respect to the mounting hole 35 a facing the mounting panel 35 in a state where the heat radiating unit 7 and the backlight unit 3 are assembled with the back panel 13. The fitting holes 26a are combined to face each other. In the liquid crystal display device 1, the optical stud members 25 are assembled to the attachment portions 35 from the inner surface side of the back panel 13 in this state. In each optical stud member 25, the fitting portion 25 b is pushed into the attachment hole 35 a of the attachment portion 35 through the fitting hole 26 a of the reflection plate 26. Each optical stud member 25 is converged by the action of the slit 25g when the fitting portion 25b passes through the mounting hole 35a and is returned to the natural state after passing through, thereby being prevented from coming off on the mounting portion 35. And assembled in an upright state.

  In the liquid crystal display device 1, as shown in FIG. 6, each optical stud member 25 sandwiches the attachment portion 35 and the reflection plate 26 in the thickness direction between the fitting portion 25b and the first receiving plate portion 25c. The reflective plate 26 is held in a state of being positioned with respect to the back panel 13. In the liquid crystal display device 1, the reflection plate 26 is precisely positioned and holds each reflection sheet piece 27. In this state, each optical stud member 25 is erected on the attachment portion 35 of the back panel 13 with the upper portion protruding from the reflection plate 26 from the first receiving plate portion 25c of the shaft-like base portion 25a.

  In the liquid crystal display device 1, a diffusion plate 23 is combined with each optical stud member 25 by fitting each fitting hole 23 a from the opposite tip portion 25 h. Each of the optical stud members 25 is allowed to move over the stepped portion 25e of the diffusion plate 23 that is pushed in the axial direction by causing the large-diameter portion to converge by the action of the meat stealing hole 17f. In each optical stud member 25, when the diffusion plate 23 gets over the step portion 25e and hits the second receiving plate portion 25d, the large diameter portion returns to the natural state, and the step portion 25e and the second receiving plate portion 25d The diffusion plate 23 is sandwiched in the thickness direction.

  In the liquid crystal display device 1, as shown in FIGS. 2 and 6, each optical stud member 25 projects an upper portion from the diffusion plate 23 from the second receiving plate portion 25 d of the shaft-like base portion 25 a. In the liquid crystal display device 1, the diffusion light guide plate 21 in which the optical function sheet laminate of the optical conversion unit 4 is superimposed on the tip end portion 25 h of each optical stud member 25 is made to abut on the bottom side thereof. Assembled.

  In the liquid crystal display device 1, each optical stud member 25 is assembled on the attachment portion 35 of the back panel 13 by a simple method of pushing the fitting portion 25b into the attachment hole 35a. In the liquid crystal display device 1, the diffusion plate 23 and the reflection plate 26 are positioned by each optical stud member 25, and the facing distance between the diffusion plate 23, the reflection plate 26, the diffusion light guide plate 21, and the optical conversion unit 4. Is held precisely. In the liquid crystal display device 1, by providing the above-described many optical stud members 25, a complicated positioning structure and interval holding structure are not necessary, and the assembly process can be simplified.

  Each optical stud member 25 can be used interchangeably with liquid crystal panels 8 of various sizes, and parts can be shared. The optical stud member 25 is not limited to the structure described above, and the specific structure of each part is appropriately changed based on the configuration of the liquid crystal display device 1. The optical stud member 25 is attached by being pushed into the mounting hole 35a of the back panel 13 by, for example, forming a slit 25g in the fitting portion 25b and imparting convergence habitability. The stop protrusion may be formed integrally and fitted into the mounting hole 35a having a key groove on the inner periphery, and then rotated to be prevented from coming off.

  In the liquid crystal display device 1, the above-described plates are precisely positioned by the optical stud member 25, so that the illumination light is converted into the light guide space portion 14 formed between the liquid crystal panel 8 and the backlight portion 3. On the other hand, operations such as light guide, diffusion, and reflection are performed in a stable state. Therefore, in the liquid crystal display device 1, the occurrence of uneven color in the liquid crystal panel 5 is prevented. Since the optical stud member 25 is made of milky white light-guiding synthetic resin material as described above, the illumination light incident on the inside from the outer peripheral surface is diffused so that the tip 25h is not partially brilliant. By doing so, the illumination light is uniformly incident on the diffusion light guide plate 21 from the light guide space portion 14.

  In the liquid crystal display device 1, specifically, as shown in FIG. 3, the above-described optical stud members 25 are located between the light emitting arrays 16 with respect to the back panel 13, and five in the horizontal direction and three in the vertical direction. A total of 15 pieces are attached. In the liquid crystal display device 1, the diffusion plate 23 on which the light control pattern 24 is formed and the reflection plate 26 in which the aluminum plate 29 and the foamable PET material 30 are joined have front and back characteristics, and must be combined without mistake. .

  As described above, the diffusing plate 23 and the reflecting plate 26 have fitting holes 23 a and 26 a through which the shaft-like base portion 25 a of the optical stud member 25 penetrates in the lateral direction corresponding to the mounting positions of the optical stud members 25. 15 in total, 3 in the vertical direction. In the liquid crystal display device 1, as shown in FIG. 3, the second optical stud member 25 </ b> A from the left side of the lower row is erected on the back panel 13 at a position different from each optical stud member 25 on the upper row side. To. In the liquid crystal display device 1, the second fitting holes 23 a and 26 a from the left side of the lower row relative to the optical stud member 25 </ b> A are connected to the diffusion plate 23 and the reflection plate 26, respectively. 26a is formed at a different position.

  Therefore, in the liquid crystal display device 1, even if the diffusion plate 23 and the reflection plate 26 are combined with the front and back being mistaken, they are combined because the fitting holes 23 a and 26 a do not exist at the position facing the optical stud member 25 A. I can't. In the liquid crystal display device 1, an erroneous combination prevention structure of the diffusion plate 23 and the reflection plate 26 is configured by such a structure. In the liquid crystal display device 1, the optical stud member 25 </ b> A, the diffusion plate 23, and the fitting holes 23 a and 26 a of the reflection plate 26 constituting the erroneous combination prevention structure may be provided at any position other than the center position. Are combined in a stable state, it is better to be provided at the inner position than at the outer peripheral position, and they may be provided at a plurality of places instead of one place.

  In the liquid crystal display device 1, a large number of LEDs 18 are provided in the backlight unit 3, and a high-capacity display is provided by supplying large-capacity illumination light to the liquid crystal panel unit 2 by the emitted light emitted from the LEDs 18. To be done. In the liquid crystal display device 1, the heat generated from each LED 18 becomes hot in the light guide space portion 14 that is sealed between the liquid crystal panel unit 2 and the backlight portion 3 and is sealed. In the liquid crystal display device 1, the characteristics of each optical function sheet of the optical conversion unit 4 described above change due to high temperature, the lighting state of each LED 18 becomes unstable, and color unevenness occurs in the liquid crystal panel 8. In addition, the operation of the electronic components constituting the circuit unit is made unstable, or a large dimensional change is caused in each constituent member.

  The liquid crystal display device 1 is configured to perform a stable operation by efficiently radiating the heat generated from each LED 18 by the heat radiating unit 7. The heat radiating section 7 includes a heat radiating plate 28 that also serves as a mounting member for each light emitting unit body 15 described above, a heat pipe 36 that is combined with the heat radiating plate 28, and an end portion of the heat pipe 36 that receives heat conduction. 13, a heat sink 37 disposed on the back side of the heat sink 37 or a cooling fan (not shown) that promotes the cooling function of the heat sink 37.

  Each heat radiation plate 28 is provided for each of the light emitting arrays 16 in six rows, and is made of an aluminum material having excellent thermal conductivity, good workability, light weight, and low price. It is formed in a long rectangular plate shape that is substantially equal in length and width. Each heat dissipating plate 28 serves as an attachment member to which three light emitting unit bodies 15 are attached, and is formed with a predetermined thickness having mechanical rigidity. In addition, about each heat radiating plate 28, it is not limited to an aluminum material, You may make it form with favorable heat conductivity, for example, an aluminum alloy material, a magnesium alloy material, a silver alloy material, a copper material, etc. Each heat dissipation plate 28 may be formed by an appropriate processing method such as pressing or cutting when the liquid crystal display device 1 is relatively small.

  As shown in FIG. 5, the three wiring boards 17 constituting the light emitting block 15 are attached to each heat radiation plate 28 with the first main surface 28 a as an attachment surface, with their end faces in the lengthwise direction abutting each other. It is done. Each heat radiating plate 28 is formed with a board fitting recess 38 that is fitted to the first main surface 28a and into which the wiring board 17 is fitted. Each heat dissipating plate 28 is formed so that the board fitting recess 38 is substantially the same width as the wiring board 17 and has a height slightly larger than the thickness thereof, and the bottom face and the width of the fitted wiring board 17. Hold both sides of the direction. Each heat dissipating plate 28 fixes the wiring board 17 fitted in the board fitting recess 38 with a plurality of mounting screws 39.

  Each of the heat radiating plates 28 is formed with a receiving convex portion 38a in the length direction in which the bottom surface of the wiring board 17 is in close contact with each other by leaving the central region in the width direction as a convex portion having a predetermined width in the substrate fitting concave portion 38. At the same time, meat stealing recesses 38b and 38c are formed over the entire length in the length direction along both sides of the receiving projection 38a. As shown in FIG. 5, each heat dissipation plate 28 is formed with a width corresponding to the LED mounting area on which each LED 18 of the wiring board 17 is mounted, as shown in FIG. Heat is efficiently transmitted from the LED mounting region that is heated so that heat is dissipated. In addition, although each heat sink plate 28 formed the meat stealing recessed part 38b, 38c in order to maintain weight reduction and dimensional accuracy, these meat stealing recessed parts 38b, 38c may also be configured as a heat pipe fitting part. .

  Each of the heat radiating plates 28 is integrally formed with reflecting plate receiving portions 40, 40 along the both sides of the opening edge of the board fitting recess 38 over the entire length direction. The reflection plate receiving portions 40, 40 are each formed of a plate-like portion protruding in the width direction from the opening edge of the board fitting recess 38 of the heat radiating plate 28, and as a whole, as shown in FIG. The surface 28 a is set to be larger than the width of the reflection sheet piece 27. The reflection plate receiving portions 40, 40 engage the side edges of the reflection sheet piece 27 combined with the light emitting unit body 15 by projecting the light emitting portions 18 a of the LEDs 18 from the respective guide holes 34.

  The reflection plate receiving portions 40 and 40 support both sides of the reflection sheet piece 27 when the reflection sheet piece 27 is formed with a width larger than the opening width of the board fitting recess 38. The reflection plate receiving portions 40, 40 are formed so as to hold the reflection sheet piece 27 combined in this case at a height position where the light emitting portion 18a of each LED 18 protrudes from the corresponding guide hole 34.

  In the heat radiating portion 7, six heat radiating plates 28 are attached to the inner surface of the back panel 13 at a predetermined interval. Each heat radiating plate 28 has three light emitting unit bodies 15 formed by mounting a predetermined number of LEDs 18 on the wiring board 17 in a board fitting recess 38, and constitutes a mounting member for six rows of light emitting arrays 16. To do. In the heat dissipating part 7, the reflecting plate 26 constituting the reflecting part 6 is assembled so as to cover each heat dissipating plate 28 in a state where the reflecting sheet piece 27 is assembled to each light emitting unit body 15.

  The inner surface of the reflection plate 26 is pressed against each of the heat radiating plates 28 on the respective reflection plate receiving portions 40, 40. Double-sided adhesive tapes 41 and 41 are bonded to the heat radiating plates 28 over the entire length of the reflection plate receiving portions 40 and 40 in advance, and the inner surface of the pressed reflection plate 26 is bonded and fixed. The reflection plate 26 supports the outer peripheral portion on the support portion 13 a formed on the back panel 13 as described above, and is held by the optical stud member 25 in the region between the light emitting arrays 16, and further configures each light emitting array 16. Also in the region of the heat radiating plate 28 to be held, it is held by the reflection plate receiving portions 40 and 40. The reflection plate 26 is positioned with high accuracy by such a structure and combined with no distortion or the like.

  In the liquid crystal display device 1, each heat radiating plate 28 constituting the heat radiating portion 7 functions as a mounting member for the light emitting unit body 15 of the backlight portion 3, and also functions as a mounting member for the reflecting plate 26 constituting the reflective portion 6. To do. In the liquid crystal display device 1, the large-sized reflection plate 26 is precisely positioned and held by a structure that also functions, thereby improving the light efficiency and preventing the occurrence of color unevenness. In the liquid crystal display device 1, the reflection plate 26 is combined with each heat radiation plate 28 by an extremely simple operation. In the liquid crystal display device 1, the reflection plate 26 is bonded by the double-sided adhesive tapes 41, 41 bonded on the reflection plate receiving portions 40, 40 of each heat radiation plate 28, but for example, the reflection plate receiving portion 40, The reflective plate 26 may be fixed by an adhesive applied on the plate 40.

  In the liquid crystal display device 1, as described above, the board fitting recess 38 is formed on the main surface of the heat radiating plate 28 over the entire length direction, and the wiring of each light emitting unit body 15 is provided in the board fitting recess 38. The substrate 17 is assembled. In the liquid crystal display device 1, the substrate fitting recess 38 is closed by joining the reflection plate 26 on the reflection plate receiving portion 40. In the liquid crystal display device 1, the LEDs 18 protrude from the guide holes 34 formed in the reflection sheet piece 27 with the outer peripheral portions thereof being in close contact with each other as described above. Therefore, in the liquid crystal display device 1, each heat dissipating plate 28 has a substrate-enclosed recess 38 as a substantially hermetic structure on the main surface side to ensure dust resistance.

  As described above, the liquid crystal display device 1 has a structure in which the substrate fitting recess 38 is formed over the entire area in the length direction with respect to the heat radiating plate 28 and thus is open to the side surface. In the liquid crystal display device 1, as shown in FIG. 4, a dustproof member 43 formed of, for example, a foamed urethane resin or a sponge material is joined on the reflection plate receiving portion 40 at the side portion of the heat radiating plate 28. In the liquid crystal display device 1, the dustproof member 43 closes the side opening portion of the substrate fitting recess 38, so that dust and the like can be prevented from entering the substrate fitting recess 38 and the dustproofness can be improved. To.

  Each heat dissipating plate 28 constitutes a heat pipe fitting recess 42 in which the heat pipe 36 is fitted on the second main surface 28b facing the first main surface 28a, and a mounting portion with the back panel 13 (not shown). A plurality of mounting studs and positioning dowels are integrally formed. The heat pipe fitting recess 42 is a cross-section that is located at a substantially central portion in the width direction and opens over the entire length direction on the second main surface 28b facing the receiving projection 38a on the first main surface 28a side. Consists of a substantially arch-shaped groove. The heat pipe fitting concave portion 42 has an opening width substantially equal to the outer diameter of the heat pipe 36, and caulking convex edges 42a and 42b are integrally formed at the opening portion.

  A heat pipe 36 is assembled in each heat pipe fitting recess 42 in each heat radiation plate 28. Each heat pipe 36 is assembled into the inside from the opening of the heat pipe fitting recess 42 and, as shown in FIG. 5, caulking processing is performed so as to close the opening against the caulking convex edges 42a and 42b. Thus, the outer peripheral portion is assembled in a state of being in close contact with the inner wall of the heat pipe fitting recess 42. Each heat pipe 36 is assembled over the entire length of the heat radiating plate 28 at a portion facing the mounting region of the LED 18 so that efficient heat radiation is performed.

  In the heat radiating portion 7, the heat pipes 36 are combined in the heat pipe fitting recesses 42 formed in the heat radiating plates 28, so that the heat radiating plates 28 also serve as holding members for the heat pipes 36. In the heat radiating portion 7, the mounting structure of the heat pipe 36 is simplified, the handling of the precise heat pipe 25 is simplified at the time of assembly and the like, and the occurrence of bending or breakage is prevented. In the heat radiating section 7, each heat radiating plate 28 is combined with the light emitting unit body 15 and the heat pipe 28 positioned and close to each other. An efficient heat conduction path is formed between them.

  In the heat radiating portion 7, each heat radiating plate 28 is combined with each light emitting unit body 15 in the board fitting concave portion 38 and the heat pipe 36 is assembled in the heat pipe fitting concave portion 42 with respect to the back panel 13. It is precisely positioned and fixed via mounting studs and positioning dowels. Note that each heat radiation plate 28 may be fixed to the inner surface of the back panel 13 using an attachment screw 39 for fixing the wiring board 17.

  In addition, in the heat radiating part 7, the heat pipe fitting recess 38 opened in the second main surface 28b of each heat radiating plate 28 is formed and the heat pipe 36 is assembled, but the structure is not limited to this. . In each heat radiating plate 28, a heat pipe fitting hole opened at at least one end in the longitudinal direction may be formed, and the heat pipe 36 may be assembled inside from the side surface direction.

  The heat pipe 36 is a member generally employed for conducting heat from a high-temperature power supply unit or the like to various heat dissipating means in various electronic devices, and is a metal pipe such as copper having excellent heat conductivity. It is configured by enclosing a conductive medium such as water that is vaporized at a predetermined temperature in a state where the inside of the material is exhausted, and has a highly efficient heat conduction capability. As described above, the heat pipe 36 is integrally assembled with each heat radiating plate 28, and both ends thereof are connected to the heat sink 37 together with each heat radiating plate 28. In the heat pipe 36, the conductive medium enclosed inside receives heat conduction from the high-temperature side heat radiating plate 28 and vaporizes from liquid to gas. In the heat pipe 36, the vaporized conductive medium flows through the pipe to the connection portion with the low-temperature heat sink 37 and is cooled, thereby releasing condensation heat and liquefying. In the heat pipe 36, the liquefied conductive medium moves to the heat radiating plate 28 side by a capillary phenomenon in a plurality of longitudinal grooves or porous layers formed on the inner wall of the metal pipe, and circulates in the pipe. As a result, it has a highly efficient heat conduction effect.

  In the liquid crystal display device 1, for example, the heat sinks 37 are attached to the back surface of the back panel 13 so as to be positioned on both sides in the length direction. Since the heat sink 37 is also used alone or in combination with the heat pipe 36 as a heat radiating member such as a power supply unit in various electronic devices or the like, a detailed description is omitted, but a large number of fins are formed by an aluminum material having excellent thermal conductivity. Are integrally formed. The heat sink 37 has a large surface area, receives heat conduction from the high temperature portion side, and dissipates heat from the surface of each fin, thereby cooling the high temperature portion.

  The larger the heat sink 37, the greater the heat dissipation effect. However, the thickness of the backlight unit 3 and the entire apparatus is increased and increased in size. The heat sink 37 is a large and heavy component. For example, when directly attached to a wiring board or the like, a heat conduction member interposed between a mounting bracket member or a high-temperature portion that retains insulation from a circuit component or a wiring pattern or the like. Etc., and the structure is complicated.

  In the liquid crystal display device 1, the large-sized heat sink 37 is skillfully arranged on the back panel 13 using the above-described many heat dissipation plates 28 and heat pipes 36, thereby suppressing the increase in size and from the backlight unit 3. It is configured to efficiently dissipate the generated heat. In the liquid crystal display device 1, the back panel 13 can be formed in a flat shape as a whole by eliminating the need to form a relief recess along the arrangement path in order to route the heat pipe 36. To do. In the liquid crystal display device 1, heat sinks 37 are mounted on both sides of the back surface of the flat back panel 13 so that a flat portion is formed in the central region of the back panel 13.

  The back panel 13 is formed into a member having a size slightly larger than the outer shape of the liquid crystal panel 8 by using, for example, an aluminum material that is relatively light and has mechanical rigidity. Since the back panel 13 itself has thermal conductivity, the back panel 13 has a function of radiating heat generated from the light guide space 14 and circuit components. As described above, the back panel 13 is formed with the outer peripheral wall portion that combines the front frame member 9 and the holder member 10 at the outer peripheral portion, and pulls out the mounting portion or lead wire to which the optical stud member 25 and the heat radiating plate 28 are attached. A drawer opening and a crossing portion are formed.

  In the liquid crystal display device 1, a liquid crystal controller that outputs an operation control signal to the liquid crystal panel 8, a power control unit that controls the liquid crystal panel 8 and the power supply unit, or an LED that controls the operation of the backlight unit 3. A control circuit package such as a control unit is provided. In the liquid crystal display device 1, the back panel 13 also serves as a mounting panel such as a control circuit package and is appropriately mounted on the back side although not shown. In the liquid crystal display device 1, various control circuit packages and the like are mounted on a control board arranged in a flat region formed in the central portion by arranging heat sinks 37 on both sides.

  Although the above-described embodiment has shown the transmissive liquid crystal display device 1 for a display panel of a television receiver having a large display screen of 30 inches or more, the present invention is applied to various liquid crystal display devices having a large screen. Of course. In addition, the present invention is extremely effective when applied to a large display device, but can also be applied to a medium-sized display device.

It is a principal part disassembled perspective view of the transmissive liquid crystal display device shown as embodiment. It is a principal part longitudinal cross-sectional view of a transmissive liquid crystal display device. It is a partially notched top view which shows the structure of a light guide part, a backlight part, and a reflection part. It is a principal part disassembled perspective view which shows the light emission unit body of a backlight part, the reflection plate of a reflection part, and a reflection sheet piece. It is a principal part longitudinal cross-sectional view which shows the light emission unit body of a backlight part, the reflection plate of a reflection part, and a reflection sheet piece. It is a principal part longitudinal cross-sectional view which shows a light guide part and an optical stud member.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Liquid crystal display device, 2 Liquid crystal panel unit, 3 Backlight part, 4 Optical conversion part, 5 Light guide part, 6 Reflection part, 7 Heat radiation part, 8 Liquid crystal panel, 13 Back panel, 14 Light guide space part, 15 Light emitting unit Body, 16 light emitting array, 17 wiring board, 18 LED, 21 diffusion light guide plate, 23 diffusion plate, 24 light control pattern, 25 optical stud member, 26 reflection plate, 27 reflection sheet piece, 28 heat dissipation plate, 29 aluminum plate, 30 Foamable PET material, 31 Guide opening, 32 Unit guide opening, 33 Bridge part, 34 Guide hole, 36 Heat pipe, 38 Substrate fitting recess, 40 Reflecting plate receiving part, 41 Double-sided adhesive tape, 42 Heat pipe fitting Joint recess

Claims (9)

A plurality of light-emitting unit bodies each having a plurality of light-emitting diodes mounted on the same axis on the main surface of the wiring board are arranged on the same axis to form a light-emitting array, and the plurality of light-emitting arrays are transmissive liquid crystals. In a backlight device for illuminating by supplying light emitted from each of the light emitting diodes to the liquid crystal panel via an optical sheet block arranged at equal intervals on the back surface of the panel,
Formed by a metal material having thermal conductivity, and formed on the main surface of the base portion is a board fitting portion that supports each of the wiring boards arranged on the same axis and arranged in the length direction. A heat dissipating plate in which a reflecting plate receiving portion is integrally erected along the side portion;
The sheet material having a reflection characteristic has a length corresponding to a predetermined number of the light emitting diodes and is formed into a rectangular piece having a width smaller than the width of the heat radiating plate, and penetrates each light emitting portion of each light emitting diode. A plurality of reflecting sheet pieces provided with a plurality of guide holes on the same axis;
A plate material having a reflection characteristic is formed to have the same outer shape as the liquid crystal panel, and a plurality of rows of guide openings are formed at positions corresponding to the light emitting arrays and penetrate the light emitting portions of the light emitting diodes. With a reflective plate,
Each of the reflection sheet pieces is assembled to the heat radiating plate by projecting the light emitting portions of the light emitting diodes opposed from the respective guide holes,
Each said light emitting diode protruded from each said guide hole of each said reflection sheet piece by superimposing said reflection plate on each said reflection sheet piece, and joining on the said reflection plate receiving part of each said heat radiating plate Projecting from the guide opening and facing the back of the liquid crystal panel. A heat pipe fitting portion is provided over the entire length direction on the bottom surface of the base portion where the substrate fitting portion is formed on each of the heat dissipation plates,
The heat pipe fitted in the heat pipe fitting part while maintaining its close contact with the inner wall, heat generated from each light emitting diode and conducted to each heat radiating plate is conducted to the heat radiating means. The backlight device according to claim 1.   The dust-dissipating elastic material is joined to each of the reflection plate receiving portions so as to seal the side openings of the substrate fitting portions to the heat dissipating plates arranged on both sides. The backlight device according to 1. Each of the guide openings formed in the reflective plate corresponding to the light emitting arrays is located on the same axis and divided into lengths that allow the light emitting diodes to pass through the bridge portion. Composed of guide openings,
2. The reflection sheet piece is pressed and held by the bridge portions toward the heat dissipation plate by the bridge portions in a state where the reflection plate is bonded onto the reflection plate receiving portion of each heat dissipation plate. The backlight device described in 1. The reflective sheet piece is formed of an insulating synthetic resin sheet material, and the reflective plate is formed using an aluminum plate as a base material.
The opening edge of each guide hole of each of the reflection sheet pieces protrudes inwardly from the opening edge of each guide opening of the reflection plate and extends to the opening edge of each guide opening and each light emission. The backlight device according to claim 1, wherein electrical insulation between the terminal portion of the diode or the terminal portion of the wiring board is maintained. A transmissive LCD panel;
A plurality of light emitting arrays, each having a plurality of light emitting diodes mounted on the same axis on the main surface of the wiring board and arranged on the same axis, are arranged at equal intervals. A backlight unit for supplying emitted light emitted from each of the light emitting diodes as illumination light to the liquid crystal panel;
A plurality of functional optical sheets, which are disposed between the liquid crystal panel and the backlight unit, are subjected to a predetermined optical conversion process on the illumination light supplied from the backlight unit and are supplied to the liquid crystal panel, and are laminated. An optical conversion unit,
A diffused light guide plate that diffuses the illumination light and supplies the diffused light guide plate to the optical conversion unit, and performs a reflection / diffusion operation and a transmission operation on the illumination light to equalize the brightness, and the illumination light is applied to the diffused light guide plate. A light guide having a light diffusion plate to supply;
A reflection part for reflecting the emitted light emitted from each light emitting diode of the backlight part to the surroundings and the illumination light reflected by the light diffusion plate to the light guide part side;
Formed on the main surface of the base portion made of a metal material having thermal conductivity is a board fitting portion for supporting the wiring boards arranged on the same axis and arranged in the length direction, and the side of the board fitting portion. A heat dissipating part having a heat dissipating plate formed integrally with a reflecting plate receiving part along the part,
The reflection part is formed in a rectangular piece shape having a length corresponding to a predetermined number of the light emitting diodes by a sheet material having reflection characteristics and having a width smaller than the width of the heat radiating plate. A position corresponding to each of the light emitting arrays formed by a plurality of reflecting sheet pieces having a plurality of guide holes penetrating the same portion on the same axis and a plate material having a reflection characteristic so as to be substantially equal to the liquid crystal panel. And a reflection plate provided with a plurality of rows of guide openings for penetrating the light emitting portions of the respective light emitting diodes,
Each of the reflection sheet pieces is assembled for each of the light emitting unit bodies by projecting the light emitting portions of the light emitting diodes opposed from the guide holes, respectively.
The reflection plate receiver of each of the heat radiating plates in a state where the plurality of the light emitting diodes, which are superimposed on the reflection sheet pieces and protrude from the guide holes, protrude from the guide openings, respectively. A liquid crystal display device characterized by being bonded on a part. The heat radiating portion is in close contact with the inner wall in each heat radiating plate and the heat pipe fitting portion formed over the entire length direction on the bottom surface of the base portion on which the board fitting portion of the heat radiating plate is formed. It is composed of a heat pipe assembled with holding
7. The liquid crystal display device according to claim 6, wherein the heat generated from each of the light emitting diodes is conducted to each of the heat radiating plates and is conducted to the heat radiating means by the heat pipe. Each of the guide openings formed in the reflective plate corresponding to the light emitting arrays is located on the same axis and divided into lengths that allow the light emitting diodes to pass through the bridge portion. Composed of guide openings,
The said reflection sheet piece is pressed and hold | maintained to the said heat radiating plate side by each said bridge | bridging part in the state in which the said reflective plate was joined on the said reflective plate receiving part of each radiating plate, The heat sink plate side is characterized by the above-mentioned. The liquid crystal display device described. The reflective sheet piece is formed of an insulating synthetic resin sheet material, and the reflective plate is formed using an aluminum plate as a base material.
The opening edge of each guide hole of each of the reflection sheet pieces protrudes inwardly from the opening edge of each guide opening of the reflection plate and extends to the opening edge of each guide opening and each light emission. The liquid crystal display device according to claim 6, wherein electrical insulation between the terminal portion of the diode or the terminal portion of the wiring board is maintained.

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